The Dutch National Institute for Public Health and the Environment, RIVM has described building blocks for a definition of microplastics. Considerations as regards criteria and threshold values serve as input for discussion at EU level.
To facilitate a quick and cost-effective screening of microplastics RIVM proposes a decision scheme. Confirmation of microplastic identity is obtained in 5 steps.
Point of departure for the definition is the broad understanding in environmental science about the general properties of microplastics. The starting point for further refinement is therefore the following description: microplastics are synthetic materials, and consist of solid particles that are smaller than 5 mm. Additionally, microplastics are insoluble in water and not degradable.
If legal or voluntary measures to reduce the emission of microplastics are to be implemented, a definition of microplastics is necessary. A definition provides legal clarity and enables the consistent monitoring of trends in microplastic pollution and the transparent evaluation of effects of policy measures.